GAP FOSS Column Metadata

GAP FOSS Column Metadata

Metadata

Data description (short)

This dataset includes zero-filled (presence and absence) observations and catch-per-unit-effort (CPUE) estimates for all identified species at for index stations by the Resource Assessment and Conservation Engineering Division (RACE) Groundfish Assessment Program (GAP) of the Alaska Fisheries Science Center (AFSC). There are no legal restrictions on access to the data. The data from this dataset are shared on the Fisheries One Stop Stop (FOSS) platform (https://www.fisheries.noaa.gov/foss/). The GitHub repository for the scripts that created this code can be found at https://github.com/afsc-gap-products/gap_public_data. For more information about codes used in the tables, please refer to the survey code books (https://www.fisheries.noaa.gov/resource/document/groundfish-survey-species-code-manual-and-data-codes-manual). These data were last updated June 01, 2023.

Data description (long)

The Resource Assessment and Conservation Engineering Division (RACE) Groundfish Assessment Program (GAP) of the Alaska Fisheries Science Center (AFSC) conducts fisheries-independent bottom trawl surveys to monitor the condition of the demersal fish and crab stocks of Alaska. These data are developed to describe the temporal distribution and abundance of commercially and ecologically important groundfish species, examine the changes in the species composition of the fauna over time and space, and describe the physical environment of the groundfish habitat.

There are no legal restrictions on access to the data. They reside in the public domain and can be freely distributed. Users must read and fully comprehend the metadata prior to use. Data should not be used beyond the limits of the source scale. Acknowledgement of NOAA, as the source from which these data were obtained, in any publications and/or other representations of these data, is suggested. These data are compiled and approved annually after each summer survey season. The data from previous years are unlikely to change substantially once published.

These data are zero-filled (presence and absence) observations from surveys conducted on fishing vessels. These surveys monitor trends in distribution and abundance of groundfish, crab, and bottom-dwelling species in Alaska’s marine ecosystems. These data include estimates of catch-per-unit-effort (CPUE) for all identified species for index stations. Some survey data are excluded, such as non-standard stations, surveys completed in earlier years using different/non-standard gear, and special tows and non-standard data collections.

Though not included in the public data, these surveys also collect oceanographic and environmental data, and biological data such as length, weight, stomach contents (to learn more about diet), otoliths (fish ear bones to learn about age), and tissue samples for genetic analysis, all of which can be shared upon special request. Also not included in the public data are estimated biomass (average total weight of all fish and crabs sampled) of crabs and groundfish that support the creation of annual stock assessments.

Column-level metadata for our public-facing data

Column name	Column name (long)	Units	Description
year	Year	year	Year the survey was conducted in.
srvy	Survey	text abbreviated	Abbreviated survey names. The column ‘srvy’ is associated with the ‘survey’ and ‘survey_id’ columns. Northern Bering Sea (NBS), Southeastern Bering Sea (EBS), Bering Sea Slope (BSS), Gulf of Alaska (GOA), Aleutian Islands (AI).
survey	Survey Name	text	Name and description of survey. The column ‘survey’ is associated with the ‘srvy’ and ‘survey_id’ columns.
survey_definition_id	Survey ID	ID code	This number uniquely identifies a survey. Name and description of survey. The column ‘survey_id’ is associated with the ‘srvy’ and ‘survey’ columns. For a complete list of surveys, review the code books.
cruise	Cruise ID	ID code	This is a six-digit number identifying the cruise number of the form: YYYY99 (where YYYY = year of the cruise; 99 = 2-digit number and is sequential; 01 denotes the first cruise that vessel made in this year, 02 is the second, etc.).
haul	Haul Number	ID code	This number uniquely identifies a sampling event (haul) within a cruise. It is a sequential number, in chronological order of occurrence.
hauljoin	Haul ID	ID code	This is a unique numeric identifier assigned to each (vessel, cruise, and haul) combination.
stratum	Stratum ID	ID code	RACE database statistical area for analyzing data. Strata were designed using bathymetry and other geographic and habitat-related elements. The strata are unique to each survey series. Stratum of value 0 indicates experimental tows.
station	Station ID	ID code	Alpha-numeric designation for the station established in the design of a survey.
vessel_name	Vessel Name	text	Name of the vessel used to collect data for that haul. The column ‘vessel_name’ is associated with the ‘vessel_id’ column. Note that it is possible for a vessel to have a new name but the same vessel id number. For a complete list of vessel ID codes, review the code books.
vessel_id	Vessel ID	ID code	ID number of the vessel used to collect data for that haul. The column ‘vessel_id’ is associated with the ‘vessel_name’ column. Note that it is possible for a vessel to have a new name but the same vessel id number. For a complete list of vessel ID codes, review the code books.
date_time	Date and Time of Haul	MM/DD/YYYY HH::MM	The date (MM/DD/YYYY) and time (HH:MM) of the beginning of the haul.
latitude_dd_start	Start Latitude (decimal degrees)	decimal degrees	Latitude (one hundred thousandth of a decimal degree) of the start of the haul.
longitude_dd_start	Start Longitude (decimal degrees)	decimal degrees	Longitude (one hundred thousandth of a decimal degree) of the start of the haul.
latitude_dd_end	End Latitude (decimal degrees)	decimal degrees	Latitude (one hundred thousandth of a decimal degree) of the end of the haul.
longitude_dd_end	End Longitude (decimal degrees)	decimal degrees	Longitude (one hundred thousandth of a decimal degree) of the end of the haul.
species_code	Taxon Code	ID code	The species code of the organism associated with the ‘common_name’ and ‘scientific_name’ columns. For a complete species list, review the code books.
itis	ITIS Taxonomic Serial Number	ID code	Species code as identified in the Integrated Taxonomic Information System (https://itis.gov/).
worms	World Register of Marine Species Taxonomic Serial Number	ID code	Species code as identified in the World Register of Marine Species (WoRMS) (https://www.marinespecies.org/).
common_name	Taxon Common Name	text	The common name of the marine organism associated with the ‘scientific_name’ and ‘species_code’ columns. For a complete species list, review the code books.
scientific_name	Taxon Scientific Name	text	The scientific name of the organism associated with the ‘common_name’ and ‘species_code’ columns. For a complete taxon list, review the code books.
taxon_confidence	Taxon Confidence Rating	category	Confidence in the ability of the survey team to correctly identify the taxon to the specified level, based solely on identification skill (e.g., not likelihood of a taxon being caught at that station on a location-by-location basis). Quality codes follow: ‘High’: High confidence and consistency. Taxonomy is stable and reliable at this level, and field identification characteristics are well known and reliable. ‘Moderate’: Moderate confidence. Taxonomy may be questionable at this level, or field identification characteristics may be variable and difficult to assess consistently. ‘Low’: Low confidence. Taxonomy is incompletely known, or reliable field identification characteristics are unknown. Documentation: Species identification confidence in the eastern Bering Sea shelf survey (1982-2008), Species identification confidence in the eastern Bering Sea slope survey (1976-2010), and Species identification confidence in the Gulf of Alaska and Aleutian Islands surveys (1980-2011).
cpue_kgkm2	Weight CPUE (kg/km2)	kilograms per kilometers squared	Catch weight (kilograms) divided by area (squared kilometers) swept by the net.
cpue_nokm2	Number CPUE (no/km2)	count per kilometers squared	Catch number (in number of organisms) per area (squared kilometers) swept by the net.
weight_kg	Taxon Weight (kg)	kilograms	Weight (thousandths of a kilogram) of individuals in a haul by taxon.
count	Taxon Count	count, whole number resolution	Total number of individuals caught in haul by taxon, represented in whole numbers.
bottom_temperature_c	Bottom Temperature (Degrees Celsius)	degrees Celsius	Bottom temperature (tenths of a degree Celsius); NA indicates removed or missing values.
surface_temperature_c	Surface Temperature (Degrees Celsius)	degrees Celsius	Surface temperature (tenths of a degree Celsius); NA indicates removed or missing values.
depth_m	Depth (m)	degrees Celsius	Bottom depth (tenths of a meter).
distance_fished_km	Distance Fished (km)	degrees Celsius	Distance the net fished (thousandths of kilometers).
net_width_m	Net Width (m)	meters	Measured or estimated distance (meters) between wingtips of the trawl.
net_height_m	Net Height (m)	meters	Measured or estimated distance (meters) between footrope and headrope of the trawl.
area_swept_km2	Area Swept (km)	kilometers	The area the net covered while the net was fishing (kilometers squared), defined as the distance fished times the net width.
duration_hr	Tow Duration (decimal hr)	hours, tenths resolution	This is the elapsed time between start and end of a haul (decimal hours).
performance	Haul Performance Code	category	This denotes what, if any, issues arose during the haul. For more information, review the code books.

U.S. Department of Commerce | National Oceanographic and Atmospheric Administration | NOAA Fisheries